Combine the like terms to create an equivalent expression: ${y-(-3y)}$
Explanation: Combine the ${y}$ terms: y − ( − 3 y ) = = ( 1 + 3 ) y 4 y { \begin{eqnarray} {y} - (-3{y}) &=& (1 + 3){y} \\ &=& 4{y} \end{eqnarray}} The simplified expression is $4y$.